ABSTRACT
Despite exhilarating advancements in our understanding of Parkinson’s disease (PD), we remain dependent on clinical criteria for its diagnosis as well as for measuring changes in disease severity due to endogenous and exogenous influences. Clinical rating scales address the need to objectively describe and define the illness but evolved primarily to detect acute, subacute, and chronic symptomatic benefits of therapeutic interventions. Later, these rating scales were also applied to the detection of neuroprotective effects and to the validation of certain biom-arkers, such as neuroimaging changes. However, rating scales have not proven useful for distinguishing between normal subjects and those with PD, or among patients with parkinsonism of different etiologies. In addition, rating scales do not well facilitate the characterization of mild, moderate, and severe disease, and they have other troublesome deficiencies. This chapter briefly reviews the history of rating scale development in PD, discusses rating scales most commonly used to measure the motor disorder in PD, and outlines goals for future scale development. The assessment of other aspects of PD, such as quality of life, affect, and cognition, is discussed elsewhere in the text.
